The growth in the number of available media channels and improved reception due to digital broadcasts has driven consumers to look beyond normal television antennas and cable systems. Digital signals broadcast from satellites are capable of providing hundreds of video, audio and data channels to users without the constraint of land line connections. The programming is distributed by a constellation of satellites parked in a geosynchronous orbit at 22,300 miles above the earth. The broadcast from orbit allows users to receive broadcasts in many areas; such as mountainous regions or desolate areas, where earth based transmitters traditionally are unable to reach.
Conventional satellite communication systems utilize microwave receiving antennas or parabolic reflector dishes connected to arms supporting feedhorns and signal converters. Cables couple the converters to receivers which provide converted output signals for televisions or computers. The antennas are typically mounted on supports fixed to the ground or a building. Antenna directional adjustors associated with the supports and antennas are used to direct the antennas toward a selected satellite. The adjustors change the elevation and azimuth angles of the antennas and maintain adjusted position of the antennas. The antenna adjustments depend on the location of the antennas relative to the surface of the earth since the satellites are in a geosynchronus orbit and remain in a fixed position relative to the earth's surface.
While such satellite systems provide a multitude of media options, in order to benefit from the service there continues to be a need to position the antenna correctly towards the appropriate satellite. In a conventional installation, an installer points the antenna with the desired elevation and azimuth to receive the signal from the contracted provider. Because a conventional installation is stationary, further tracking or adjustments are not necessary once the installation is complete.
The positioning of a receiver antenna becomes problematic when the receiver antenna is mounted to a mobile unit. When the satellite communication systems are moved to a new location, the elevation and azimuth angles of the antenna must be adjusted to align the antenna with the selected satellite. Determining satellite location is especially problematic to the user who may be in a new location every night. Such users wish to attach a satellite receiver system to a bus, boat, motor home, trailer, commercial vehicle, van, camper or other mobile unit. For example, many buses and recreational vehicles install satellites receiver systems on the roof of the vehicle. When they park at night they may have to first position the antenna to an operating position and then adjust elevation and azimuth position to locate the desired satellite.
Currently there are a wide variety of satellite antenna systems available. The earliest models were tripod or post type dishes that were mounted on the ground and manually aimed. Advances and increased market usage created a need for roof top mounted systems. The initial versions also used a crank to manually aim an exposed satellite dish at a satellite. The manual component of aiming the dish generally contributed to poor reception. Furthermore, the manual aspect required the user to either run back and forth from the dish to the television to check on signal or recruit a helper to notify the user when the satellite dish was aligned properly. The manual units are likely to have poor reception due to the difficulty in finding a satellite.
While inexpensive, the manually aimed, exposed dish systems are easily damaged by the environment. These antennas are exposed to wind, insects, mud, dirt, dust, snow, ice and ultraviolet radiation. In some installations the exposed dishes are pivoted to a generally horizontal non-functional position when the vehicle is moving to reduce the wind forces on the dish. In addition, environmental conditions such as high wind may shut down operation for an unprotected system due to misaiming the focal point. To avoid the problems outlined above, dome systems were introduced to protect the dish. Covered systems allow the dish to always remain in an upright protected position.
In order to further enhance signal quality, fully automatic tracking system were developed. These systems are expensive due to the complex tracking algorithms and motor control required to automatically recognize position and then conduct a search of the sky. These high costs preclude their use by many consumers. Moreover, the details required to perform an automatic search are often time sensitive. Changes in programming, satellite constellation locations create compatibility issues that require software changes that further increase cost.
Therefore, there is a need then for a low cost environmentally protected satellite receiver system capable of providing television, radio and Internet reception to users who are unable to receive the respective signal through a conventional land line or are viewing from a mobile position that requires locating the satellite signal. The system should be robust enough to survive travel. Furthermore, the locating mechanism should be simple enough for the user to locate the satellite before each use by incorporation of an easily programmable satellite locator system.